textproduct: Quad Cities

KEY MESSAGES

- Slightly below normal temperatures are expected today and Saturday, with chances for showers and isolated thunder late this afternoon into tonight.

- Heavy rainfall is expected with a system late Saturday night through early Monday morning. Accumulations of 1-3 inches are likely (50-80%) south of Highway 20, with uncertainty in where the greatest rainfall will be.

- Comfortable temperatures are expected to continue through much of next week as we stay under northwesterly flow.

SHORT TERM /THROUGH SATURDAY/

Issued at 202 AM CDT Fri Jun 19 2026

A series of embedded shortwaves can be seen on water vapor imagery this morning. The first of these is moving into the Great Lakes after producing an isolated band of showers across eastern Iowa and northwest Illinois late last night. As it exits, upper level ridging will build in, setting the stage for a pleasant morning. Expect clear skies through midday, at which point a diurnal deck of clouds will develop ahead of another shortwave. By late afternoon, scattered light showers and thunderstorms will move in and last through late evening, primarily north of Interstate 80. Accumulations are expected to be light given the limited moisture return ahead of this shortwave, with a 60-70% chance of rainfall not exceeding 0.10 inches. Locally higher amounts up to 0.25 inches will be possible in areas that experience heavy showers.

Saturday, upper level ridging will bring another pleasant but cool day for mid-June, with highs once again in the upper 70s to low 80s and light westerly to northwesterly winds.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Issued at 202 AM CDT Fri Jun 19 2026

Saturday night, a stronger shortwave is expected to eject into the central Plains. WAA ahead of the shortwave will bring in moisture, though there is uncertainty in how much moisture will reach the region. This is due to a number of factors, with the greatest being uncertainty in the track of the shortwave and a potential MCS. Guidance falls into two potential scenarios regarding this: one with the track across northern and central Missouri (impacts greatest south of Interstate 80), and the other with the track across southern Iowa (impacts greatest area-wide).

With both of these scenarios, widespread rainfall is expected Saturday night through early Monday morning, with the primary question being where the heaviest rainfall will occur. NBM probabilities have a 50-80% chance of exceeding 2 inches of rainfall south of Highway 20 from Saturday morning to Monday morning, though the blended nature of the NBM combines the two potential scenarios. The areas with highest confidence in high rainfall accumulations are south of Interstate 80, as heavy rain in this area will be a given with either scenario. As a result, there is a Slight (Level 2 of 4) risk of flash flooding on Sunday.

A secondary question is the thunderstorm potential, and with that, the chance for severe thunderstorms. Similar to heavy rainfall, the best chances for thunderstorms will be south of Interstate 80, where instability will be greatest. Meanwhile, severe risks appear more conditional, with the greatest shear and instability kept to our south in both scenarios. With uncertainty in both the track and timing, this remains one area to watch in the coming days.

Past Monday, northwesterly upper level flow will continue, maintaining our below normal temperatures for June. With this comes the potential for additional rainfall as disturbances move through the flow.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 630 AM CDT Fri Jun 19 2026

The forecast remains on track with prevailing VFR expected through the day, along with light winds. Confidence is increasing in scattered showers and isolated thunderstorms moving in from the northwest in the 20Z/19 to 03Z/20 window, which will bring the potential for MVFR visibilities and brief gusty winds.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.